De-risking drilling to secure on-farm water supplies

[Music] Hi, I'm Doug Hamilton, Drought Hub Innovation Specialist. The dry season resources podcast is brought to you by the South West WA Drought Resilience Adoption and Innovation Hub, and is funded through the Future Drought Fund. This episode was recorded on the lands of the Wajak Nungar people. [Music] I'm hosting this innovation series for the podcast, which focuses on how farmers, agronomists and consultants are adopt, and then adapt innovations to suit their local needs, and improve their climate and economic resilience. Securing reliable water supplies are one of the most pressing challenges facing Western Australia's weak-belt farmers in a drying climate. I'm joined by Dr. Richard George from Deep Hood, and Professor Brett Harris from Curtin University, to unpack a research and industry engagement project, designed to unlock the currently underutilised water sources within the WA Wheatbelts Fractured Bedrock Actors. Welcome to the podcast. Richard, starting with yourself, could you please provide an introduction? Richard George from Department of Primary Industries and Regions of Development. I lead a water group in D-Pert. We work from the northern parts of West Australia through the South, but a lot of what we've done in the last five years have been trying to develop safe, new and reliable water supplies for dry land agriculture. Across to you now, Professor Harris. I'm Brett Harris from Curtin University. I'm the Dispunt Lead for Geophysics here, but I'm working with Deep Hood on finding open fraction networks in the subsurface. That's Bedrock aquifers. The overarching objective is to find long-term water supply, but principally, minimizing the risk, when drilling, to find these Bedrock aquifers. Let's start getting into some of the content. Richard, starting with yourself, do you want to give us a bit of a broad overview of the Water Smart Dam's project and how this fraction bedrock aquifer project has come about? Yeah, thanks Doug. So the package of Water Smart Farms developed in the back of 2019 into 20 years after we'd been through three dry seasons. The logic was to try and develop not only increasing the reliability of our surface water, which the Water Smart Dam's project and GGA had a lot to do with, but was to look at some new and more novel approaches of finding water. So one of the last places that hadn't been worked on any detail was really that granite country at depth under the wheat bill, below the clays, below the salty soils that are common, to see if we could find water in those cracks where there had been success in some holes, but there was no methodology to try and increase the reliability of that water supply. And the other part of that project was if the water was available and you didn't need to deselinate it, then that was a bonus. But if you got good water supplies and you needed a really strong underpinning for your farm, then you had the option of deselination as a fallback. But this project was to value out all the other groundwater work that's been done. So there is still groundwater supplies out there next to big granite rocks. There's groundwater in sand plain and there's groundwater at the top sitting on top of the bedrock. But we knew that there was also groundwater in the rock. And this process was to work out how we could find that where it existed and where to find it with its best water quality. So moving in a little bit deeper into the fractured rock bedrock projects, I believe it's phase one is now wrapped up. And do you want to provide a few standout findings or anything that surprised you through the process of delivering phase one? So I'll start and say that phase one was a partnership with about a dozen farmers, where we work with them to locate the right place on their farms to start this exploration. Brett and I'll talk through the way we did that and the geophysics tools that we used to do that. But there's some principles that we tried to test. And if you like, the standout results was at 75% of those sites, we achieved our target groundwater supply, which was 50,000 litres a day. And at more than 50% of those sites, we achieved our target salinity, which was under 5,000 parts. So essentially good livestock water. Over to yourself, Brett, any particular standout findings from your point of view. I think the standout binding was the way we used magnetics. We have these beautiful structures that cross the entire weep belt region. They can be 500 kilometres long. And they're extraordinarily well defined in our magnetic data. But what they allow us to do is to target structures that cross them. And that enabled us to target very accurately the open fracturing. The thing about those fractured zones, they have different permeability or different ability to transmit water. So then we need to be clever about the way we drilled holes through those zones. Though that we intersect, they had the optimum chance of intersecting open fractures at the right depth. And remember that there's a whole lot of other analysis that goes along with this. Like the landscape, how close you are to the salt lakes, all of those things. But in the end, we came up with a target where we anticipated intersecting open fracturing based on very precise targeting of ground magnetic data. And that was just highly successful. I guess that's the simple finding. Whereas previously, the success rate for intersecting open fractures was relatively low. One in 20 is not an unreasonable number. It really depends on context as well. So if you say 50,000 liters a day is the cut off, then that's reasonable. But our other holes also yielded significant amounts of water. So some farmers, 20,000 liters a day, maybe absolutely fine. So historically, the week belt drilling unusually gets better than one in five. Historical programs have been one in 10. We ended up drilling around about 20 holes at these over a dozen sites. And if you scored them on the basis of did we find water above the rock at 17 of the holes, there was no water above the rock. And only at one site was there yielding water above the rock. As I said previously, we had 75% of these hit water in the bedrock. The context there is we're trying to drill high in the landscape, the top third of the landscape, where you don't have a lot of water sitting on top of the rock. And we're staying away from the valleys where there is a lot of water. But it's also most often say-lone. So we're cherry picking the part of the landscape where we're trying to find water. And we try to use the tools that Brett's described with fractures and magnetics to give us those targets, to get us from resolutions of hundreds meters to kilometers into target zones, less than 20 by 20 meters as a target structure. Interesting outcome is that we did a few experiments where we walked off our principal target by 20 meters and got significantly less yield. So getting that very high resolution from a landscape where the cover is thin and the basement rock, which contains the mineral that the magnetic method is sensitive to and interpreting it within a context of a model that yielded good results. And I guess moving forward, we would hope that that can be replicated. But you know, we only have a small sample. It's something I'd like to explore a bit more with you, Brett, is what made you choose magnetics? We have sites where we collected a range of data sets. We have collected very, very high resolution in seismic data sets. We have collected time-domain at the end data sets. All those two techniques are particularly sensitive to what's happening in the shallow zone, that zone above the bedrock. However, the only technique that has got the mineral distribution is the magnetic method. Because it's basically highly sensitive to the distribution of a mineral called magnetite. And that magnetite doesn't exist in the cover. It only really exists in the bedrock. So for targeting structures and fractures very accurately, high in the landscape where the bedrock is shallow, magnetics provides a very detailed image. And if we've got a correct model of where the fracture should be, then magnetic method is superior to others. That's not to say the others can't contribute to an overall picture. How deep does the magnetics go down to the bedrock? The magnetics just detects everything, but it has a drop-off in resolution with depth where we have them cover. It's able to produce a very, very high resolution image. And we can track the shape of subsurface bodies to greater depth when you're doing the surveys, electromagnetic adoption, so dragging a sled around. Is this similar? Magnetics is collected from aircraft and we have that baseline data set, which is a huge advantage. But the further you are away from the source of the magnetic field, so that is the magnetite or the lower the resolution. So if you're flying at 50 meters, the resolution that we need is not achievable, but the general or global picture is there. So we can use the global picture to select sites that we go to on the ground to do very high resolution ground surveys from which we can target holes very accurately. We do have to go through a series of steps, so use the landscape, use the airborne magnetics, pick your site, then do the very high resolution ground magnetics, then interpret the ground magnetics, basically target the depth that we're interested in, cut target the structures, and often we are targeting two structures that may be perpendicular or subperpendicular to each other, and then hopefully drill a hole into sex of open fracturing. Let's move on to phase two, which is the voucher program, which you'd want to put a bit more flesh on the bones around who is it designed for and what you hope to get out of it. The voucher process is a shared risk R&D project. We're 50 partner farmers look to take the method that we developed in Phase 1 and apply it in a range of landscapes at a range of farms in Phase 2. Essentially the difference is that we didn't cherry pick the sites if you like, whereas we have a lot more control over the sites in Phase 1. The application process means we're getting farmers from right across the wheat belt with arranger conditions. And so we've got to try and find optimum sites from a much more diverse background of landscape types, which means we're putting the method to a much higher level of test to make sure that we've got repeatability. The second part is to test the method and make sure that from an extension and value proposition for all the farmers that follow, we can give them reasoned guidance about what chance of success they've got. And so the voucher program, it's finished now, is there going to be another round? The first phase of the program has shut. We're currently going assessing all that. I think application 97 was the last one that I looked at the other day and that's it. We've got, if the site qualities don't give us everything we want, there may be an opportunity to go open it up a second time round. But let's cross that bridge later. We've got a great list of partner farmers who've applied. We're going to work through all of those with those guys, those farms under different conditions. We also learnt a lot about their risks from the questionnaire that we ask them to context these surveys. And we've got some great data on what water means, what it costs and what impact it's likely to have on not having it on their business. And particular with food lighting where we're changing the intensity of animals from across the whole farm to very specific areas in a farm that's changing their dynamics and the risk of having risky water supplies. So having reliable on farm water sources can really change the decisions that a farmer can make through a dry season and in your experiences, Richard, what do you see as being those decisions that farms can now make when they have that reliable source? Our Water Smart project, we're chasing down one of the newer options to try and find groundwater in the week belt. Historically, it wasn't done because those sort of rigs didn't exist. And the results have previously been reasonably poor, depending on where you were. So I think the core message is we're doing the R&D to help the planning by adding more water supply options for farmers. That doesn't mean that aren't already options and farmers are generally aware of most of the surface water supply options. I think farmers have learnt in those years where there are consecutive dry seasons how difficult even the most reliable water supplies are. The scheme is probably the most reliable, but it's not everywhere. And when everyone wants it, the pressures drop and you've got to drive a lot of miles. We were seeing some farmers respond to us that they were spending $60 plus $1000 in direct costs to get water and those sort of seasons. They're large overheads that no business wants to carry. We're adding another component to the list of options. There are plenty of options out there, but you need some level of risk assessment. And not all the week belt is suitable for every option, and that's a key learning from the last five years. So what we need to do as researchers is provide that understanding about why you would invest in bedrock exploration, but also where you wouldn't invest in bedrock exploration. So both outcomes are good. I would emphasize that having a well on your property is a very long term water supply. So it's not dependent on the weather or not as dependent as dams and 50,000 litre per day. It's not for a week or a month. It's a water supplier that our thoughts at this stage is that they are very secure long time term water supplies once they've been pumped tested. And I will say something else about the process so far is that it's transparent. We are able to say here's the process that we went through on multiple sites starting with the airborne magnetics, the ground magnetics and it's visible. So Richards can put up a map. I'm saying this is what the magnetics looks like. This is where we drilled. This is why we drilled. This is the outcomes we get. This is the yield. This is the salinity. And the whole story is right there in front of a farmer from start to finish. We do have farmers from the first phase and Richard will know better how they're progressing who are using wells that we are targeted at four water, which you know the two or three sites. At least three or four put these systems into action. They've got different needs at different flow rates, but from 20,000 litres a day up to 90,000 litres a day are being taken out of those holes and some of those holes are now been running for two years at those rates. Their quality of the water resource are not the key parameter that's worth looking at when in the context of things like spray program is well. Yeah, so the thing that the Fracture Rock Program is it allows us to go higher in the landscape where the quality is better, but that doesn't mean it's going to be fresh. You know, the best water quality for some landscapes may well be somewhere between lambs and lactating shoes. In other landscapes it might be sitting up at dry sheep equivalent numbers. So we find that large amounts of water that well is going to see a large amount of country long yielding. It means it's going to be doortering across hundreds of hectares of landscape. How this links into some unity further down the landscape. Do it just touch on that briefly Richard. Sure, I think it's important to realise that this water supply that we're targeting and generally across the wheat belt a lot of it's only been there for a hundred years since clearing. So that water which is building and water tables is still rising across significant parts of the wheat belt. So if we can intercept this water high in the landscape while it's still a reasonable quality, that's less water that's going to end up lower in the landscape and coming out of a saline patch. That's not to say we could ever pull out the amount of water from these boys to solve the weak dot salinity problem. We do have a couple of farmers who have got D cell plants that have had great success at clearing up small sand plowing salinity problems by using this groundwater. But that's not the most common outcome. I think the point is that this water in excess it can cause a problem somewhere else. So rather than pump it you know 300 kilometers from a D cell plant on the coast. If we can find it under the farm, let's have a go there first. Most lot of sense now let's look at moving beyond individual farms through to what the broader industry uptake can look like in terms of this targeted water exploration. In your thoughts, Richard, what would need to happen to get to that broader industry uptake beyond phase two success? The goal of this project is obviously to do the R&D to reduce the risk and to develop that model if you like that says undertake these works and you should get this outcome. The practical way of doing that is we use the state's airborne data and we're testing the levels of ground survey that is required and that the level of processing that Brett's doing through curtain develops a workflow which other companies can then run through and use. So just like everything else in agriculture, we're developing a method, third parties that are experienced in doing this in other context can take up that methodology. They can apply and develop on from this method. They can do it better with more data. And then the last part of it is then having drillers that are informed on why it works and then can take that into practice. We've got several companies who can do the geophysics and we've worked on them with the method that Brett's team is developed and we've also got about 20 or 30 drillers who work across the wheat bill who have approached us to learn this technique so that they can then be the next level of extension because at the end of the day you go put a hole in the ground. So if those drillers are aware what we're looking for and they understand the interpretation process that goes on then farmers can take on those services from companies that understand the method and give them the best chance of an outcome. I think that's absolutely the direction. We have a lot of research around bits and pieces, translating that to industrial outcome is the best possible outcome. But also a springboard for the geophysical companies drilling companies to basically engage in this process. An interesting thing from everyone's perspective is that these structures that run across the wheat billed our 500 kilometers long. So if we have a successful method for targeting along those structures will open up options for water supply that may not have been considered before. And our future with increasing quality and cost-effective dissemination system is not improbable which knows more about the deceleration and success of those pilot projects. But the whole world of dissemination is rapidly evolving and also the thing that fits nicely and that is the reduction in the cost of energy if you start to look at putting it onto photovoltaics and just running it during the day. Which is anything else you'd like to add into that. From the context of water supplies I think the main thing is you've got multiple options. Don't throw any away at the moment. The scheme is highly reliable when you've got it but there's a cost and pressure component when everyone wants it. Farmers through what they've told us across the last five years want to have the capacity to manage their own supplies. And they'll work out their quality constraints and deceleration is just another tool to change the quality to be what you want it to be. So we're giving people options the number of holes that are going into the bedrock was minute a decade ago it's now I think we've got 25 rigs in private operation supplying service to farmers. So the industry is growing we know we've got excess water in the wheat bill that's not like the coast where water levels are dropping and we're running out of water. The wheat belt's sadly got more water than it wants. It's just that it's brackish salty and you've got to work really hard to find the fresh bits. the Taka message from me is. don't wait for those two or three bad years. The planning takes place now. The implementation takes place before that event. What Brett is helping us with is the technology and the interpretive skills and tools. What we're doing with the growers is increasing the diversity of sites that we're trying to test from. In some cases, we're going to sites that very hard to find water. So we're not choosing, you know, the Goldilocks site on every instance. So we're going to get a real diversity of outcomes from this process of working with 50 farmers, but those 50 experiences will be bundled together and potentially using AI tools and the state's data. We will be able to come through with a raft of next generation target sites and let's not get too far ahead of ourselves. Let's drill these holes. Let's take these surveys through the completion. We got good results out of phase one. Let's see how we go with those two. That's a really great takeaway. Take that action now. Start with a water audit and then start evaluating what your supply can look like. From yourself, Freddy, is there anything in terms of takeaway for farmers? Listen to this conversation. I think Richard's absolutely correct. If you've got an option that is all mapped out that farmers can take on in the future, rather than waiting for the future to happen, I think that's hugely valuable. So if we find methods for making prospectivity maps for open fractures, that means that should a extended or period of drought occur in the future, then farmers can quickly implement a solution that will mitigate very difficult circumstances that did occur a few years ago. I think we haven't really talked a lot about cost and it's a reasonable expectation to try and understand what this sort of thing adds. So we're using state data that's already been acquired to give us the capacity to look at every farm and under every farm, the structures that Brett's described exist. The question about many farms is how much salty cover they've got over the top, which makes these fractures redundant because they're going to be filled up with saline water. So the first thing is just because you've got the right geology underneath, doesn't mean you've got the right salinity that's going to fill up those fractures. So that's an important thing. The targeting that we're doing, we're talking about spending about $10,000 at a property level to do the targeting and we're talking it somewhere around about 20, 25,000 to do the exploration. So that's the overhead before you know the answer, building a dam is not cheap, putting a plastic catchment on is not cheap, connecting up a scheme and managing a scheme is not cheap. So you've got to see all these costs in relative likelihood of success. And so I'm just adding those costs. So growers can get a sense of what this actually costs to be going down the pathway, but the more that we can reduce the overhead around site definition, that means you're only got that risk at drilling the district rate, the point it's not one solution for everything. It's look at what your supply options are, look at what your costs are and look at what are the best options for you to invest in, but it's not going to be one. Anything further from yourself bread in terms of takeaways from the conversation. Not really. I just think that we've come from a very low base and we're kind of accelerating our understanding this next phase will basically be a permanent record of how this process can occur that will be water supply. So we have been guided by by price as well. We have been deployed a 3D seismic, which is going to cost hundreds of thousands of dollars per square kilometer. That's just not practical. And we also have tested really expensive techniques on very small areas and really haven't seen the benefit. So the magnetics is a very nice technique for us to use because it's low cost and it has generated good results. So we have practical clear outcomes from a very clear process. Just I'm thinking about things that are the next steps. Clearly we've got the the foundations of some of those tools and that's what I'm using to do the site selection of these 50 sites and some of the lessons and learnings from that will go into training packages about how much we can expect to pass on. How much of that knowledge is simple to absorb? How much that knowledge is special, so you want third parties to do four you wills a grower. So you know, I guess I'm just flagging that we've got tools and technologies that we're using to do this work prior to doing the high resolution ground surveys. And from a university perspective, we are also training students with these datasets, Richard and deeper to be fantastic and support basically education at the university level and these are fantastic, all tier and physical method datasets that are collected with drill holes. So perfect for students to a good story. Yeah, it is a great story and it really yields that capacity in the industry and helps provide that resilience moving forward. I've really enjoyed this conversation and I think it's just such a great project. And it's really great to see the support of all the different funders and players, state government and also industry engagement in SO well done on a great project and all the best with FACE too and coming out the end of that. So thank you very much, Richard and Brett. Thank you for listening to the South West WA and Drought Hub's Dry Season Resources podcast. For further support on decision making through dry periods, a collection of resources can be found on the Drought Hub website hub. GGA.org.au [Music]